Havas was the last ad agency client of Andersen, which shut down its U.S. audit practice in August after it was found guilty of obstruction of justice related to its work with Enron Corp.

As for Andersen's former ad clients, Omnicom Group hired KPMG, Modem Media hired PricewaterhouseCoopers and WPP Group switched to Deloitte & Touche. Bcom3 Group, which was acquired by Publicis last month, had switched to Ernst & Young in May.